ME DAVID MILNE HOME ON THE BOULDER-CLAY OF EUROPE. 663 



ings is from W. by N. to E. by S., so that the polishing agency must have crossed 

 the hills at an angle of 30°." 



Dumbarton and Renfrew shires. — Dr Chambers mentions that on the sand- 

 stone plateau between Campsie and Stirling, the striations on the rocks were 

 W. 20° N. 



Having myself visited the moors, about three miles N.W. of Milngavie, in the 

 parish of Baldernock, I found the white sandstone rocks ground down and 

 flattened in large patches, with strise and rents on them, indicating a movement 

 from W.N.W. and N.W. (magnetic.) 



The late Mr Smith of Jordanhall, in his Geological Researches, after enumerat- 

 ing several localities where boulders of various kinds of rock had been examined 

 by him in Clydesdale, observes — " In these cases, the bearing of the supposed 

 parent rocks is N.W. ; but in all of them the intervening space is intersected by 

 deep arms of the sea and steep mountain ranges (p. 13). One of the boulders 

 was found in the boulder-clay near Airdrie, the nearest granite rock being at 

 Cruachan, about 60 miles N.W. of Airdrie." Mr Smith adds — " I never yet 

 saw or heard of an erratic block in the valley of the Clyde, whose course could 

 be traced, that did not come in an opposite direction to the flow of the river. 

 We can trace their course, not from the mountains to the sea, but from the sea 

 to the mountains " (p. 131). 



Edinburghshire. — The general direction of the movement in this district has 

 been very accurately ascertained by Sir James Hall, Mr Maclaren, Dr Fleming, 

 Robert Chambers, Mr Nicol, Hugh Miller, Mr Geikie, and myself. All concur 

 in representing that the movement has been from points varying between W. by 

 S. and N.W., the most prevalent being from W. by N. (magnetic). The evidence 

 of this is well stated by Mr Geikie in the following passage in his Memoir of the 

 Geological Survey, No. 32 : — " The parallelism of the striations throughout the 

 district show that the floating ice must have moved in a pretty uniform direction ; 

 and that it was from the west, is clear by the striation of the western face of the 

 hills, the great depth of the drift on their eastern sides, and by the fact that the 

 transported boulders, when traceable to their parent rock, have been carried from 

 west to east." Mr Geikie then specifies several of these boulders on the Pentland 

 Hills, and one in particular of mica slate, first noticed by Mr Maclaren, weigh- 

 ing eight or ten tons, and at a height of 1060 feet above the sea, which he says 

 had " undoubtedly been transported from Cantyre or the Grampians." These 

 boulders Mr Geikie at that time considered to be " ice-borne blocks dropped on 

 the submarine slopes of the Pentlands." Whether he now thinks that they were 

 brought by the agency of a glacier, I do not know. 



Stirlingshire and Lanarkshire. — On the west side of Damyat (one of the 

 Ochils) I found, at a height of from 500 to 600 feet, many patches of hard con- 

 glomerate rock, ground down and striated by an agent which had come from the 

 vol. xxv. part ii. 8 K 



